Vibrator mechanism for belt sander



2 Sheets-Sheet 1 Wd/Vz @Tx/Zamba@ BY @M )ffm March 5, 1963 w. A, EscHENBuRG VIBRATOR MECHANISM FOR BELT SANDER Filed April 14, 1961 March 5, 1963 w. A. EscHENBURG 3,079,734

VIBRATOR MECHANISM FOR BELT SANDER 2 Sheets-Sheet 2 Filed April 14. l21.961

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United States Patent O 3,679,734 VERATGR hECi-ENISM FR BELT SANDER William A. Eschenhurg, Beloit, Wis., assigner to Yates- American Machine Company, Beloit, Wis., a corporation ot' Delaware Filed Apr. i4, 1963., Ser. No. 193,651 6 Claims. (El. Sl-lfl This invention relates to surface treating machines and is more particularly concerned with improvements in machines for abrading or polishing the surfaces of wood or similar materials by engaging the same with a traveling abrasive coated belt.

Surface abrading machines have heretofore been provided for finishing wood panels or like members having at surfaces which employ an abrasive coated, traveling belt. In general, such machines have been employed for ne iinish work only since the depth of cut is relatively small and the scratch line pattern produced is generally not so prominent as to be objectionable. Rough surfacing to reduce the thickness or prepare the surface for a line nishing or polishing operation has usually been `accomplished with machines employing abrasive coated rolls or drums. In copending application Serial No. 830,004, filed July 2S, 1959, drum and belt sanding are both employed, provision beingT made for rirst passing the worl; piece beneath a sanding drum unit so as to remove a substantial amount of material and reduce the work piece to a definite thickness and then passing the work piece immediately beneath one or more vertically disposed sanding belt units for obtaining a line iinish. In the operation of this machine, it has been found that a more satisfactory surface polish can be obtained if lateral vibration or oscillation can be imparted to the traveling belt and it is a general object of this invention to provide a mechanism for satisfactorily accomplishing such belt movement in one or more of the sanding belt units.

It is a more specific object of the invention to provide in a roll supported traveling belt-type surface finishing machine a mechanism for vibrating in an axial path one of the rolls which support the belt.

It is another object of the invention to provide a mechanism associated with one of the supporting rolls of a traveling belt-type -surfa'ce finishing apparatus which is effective to impart a reciprocating movement of relatively small amplitude and comparatively high speed in the direction of the axis of the roll.

It is a further obect of the invention to provide an improvement in belt-type sanding machines which comprises mounting on the bearing support at one end of a ybelt supporting roll an apparatus for vibrating the roll in an axial path which permits the bearing support to be oscillated in a path generally normal to the axis of the roll.

These and other objects and advantages of the invention will be understood from a consideration of the apparatus which is shown by way of illustration in the accompanying drawings wherein:

FIGURE l is an elevational view with portions broken away of a belt sander having a vibrator mechanism incorporated therein which embodies the principal features of the invention;

FIGURE 2 is a partial side elevation, at the bottom of the machine, to an enlarged scale;

FIGURE 3 is a fragmentary section taken on the line 3 3 of FIGURE 1, to an enlarged scale;

FIGURE 4 is a partial side elevation at the top of the machine, to a still larger scale;

FIGURE 5 is a sectional View taken on the line 5 5 of FIGURE 4; and

FIGURE 6 is a fragmentary section taken on the line 6 6 of FIGURE 4.

Patented Mar. 5, 3.963

Referring to FIGURE l of the drawings, the invention is illustrated as incorporated in a belt sanding apparatus or unit of the vertically disposed type which is particularly adapted to be employed in the combination sander described in copending application Serial No. 830,904. The illustrated unit is capable also of independent use when properly supported above a feed table and connected to a suitable motor or other power drive mechamsm.

The illustrated unit comprises a frame 1U carrying upper and lower rolls or cylinders il and l2 on which `a relatively wide abrasive coated belt 13 is adapted to be supported. The principal member of the frame iti is a cross beam I4 which is supported primarily at one side of the machine by an upstanding portion i5 of a main supporting frame le so that the cross beam l@ extends with its major portion projecting in cantilever fashion across a work supporting traveling conveyor indicator at 17.

The front end of the cross beam 14 is supported and locked in position relative to the front portion of the main supporting frame 16 by means of a swinging frame or lock member 13 (FIGURES l and 2) which has the form, when in closed position, or" an inverted V and which is mounted at its lower end on the main frame l@ by means of a pair of longitudinally spaced bearing brackets 19 and 19l which receive the ends of a pivot pin 26 carried in the ends of the legs of the member 1S. At its upper or apex end the lock member i8 has a headed locking bolt 2l (FIGURES l and 2) which is rotatably mounted on the frame and adapted to engage its threaded inner end in a threaded socket 22 in a downwardly projecting end bracket 23 which is secured on the end of the cross beam 14. 'Ihe locking arm l is adapted to be swung on the pivot pin 2t) outwardly of the machine to an open position to permit the belt i3 to be removed endwise of the rolls il and l2 when 4belt replacement is desired. The lower belt carrying roll 12 which constitutes the contact or pressure roll for holding the belt against the work has the ends of its supporting shaft 24 journaled in bearings 2S and 25 which are carried in swingably mounted, transversely spaced support arms 215 and 26. The support arms 26 and 26 are mounted at one end on pivots 27, 27 which are secured on the bottom of the cross beam 14. The pivots 27 and 27 have their axes aligned transversely of the machine so that the support arms 25 and 26 form a swinging support frame for the roll 12. The support arms 26 and 26 extend in a generally horizontal direction and each arm, as shown in FIGURE 3, carries intermediate its ends an upstanding pin or bolt 23 which projects through an aperture 3i? in the bottom of a pocket 3l in the bracket 23 and through a compression spring 32,. An adjustable end stop nut 33 is provided on the top end of the bolt 2S against which the spring 32 engages so as to normally urge the roll support arms in an upper direction away from the work supporting bed of the machine.

Mechanism for adjusting the elevation of the roll fr?, is provided which engages with upwardly extending end portions 34 and 34 (FGURES l to 3) on the roll support arms 2d and 26' and moves the arms downwardly against the force of the springs 32. The upper edges or faces of the arm extensions 34 and 34 engage the beveled surfaces of a pair of wedge-shaped lock members 3S and 35 which are carried on right and left hand threaded ends of an operating cross shaft 36, the latter being journaled at its opposite ends in portions of downwardly extending brackets 23 and 23 on the cross beam 'le and having one end extended and squared to receive an operating handle or wheel (not shown). The depending bracket f formations 23 land 23' at the ends of the cross beam la anveres wedges 35 and 35'. The contact or pressure roll '12 may" be rubber covered with spiral grooves or it may 'have any other surface suitable for receiving the Ybelt 1S 'and applying pressure through the belt as the work is carried beneath the unit. The roll shaft 24 is extended .at theY rear side of the machine and is connected with `a suitable power -drive (not shown).

The upper belt tensioning roll 11 has the opposite Aends of -its supporting shaft 6% mounted in bearing carrying bracket members 41 and 41 (FIGURES 1, 4 and 5) which are supported on the upper ends of vertically disposed pistons 42 and 42', the latter extending upwardly of 'hydraulic cylinders Vd3 and 43 'which are mounted in vertically extending lrecesses 44 vand del in the ends of the cross beam 14. At the rear side of the machine the bearing bracket 41 is secured by a vertical VpinliS which extends upwardly of the end of the piston 42'. The bearing in the bracket 41' is self-aligning and will permit the roll 12 to swing a limited amount in a horizontal .plane above the vertical axis of its support. It is also slidable in the axial ydirection in the bracket 41'.

At the front side of the machine the bearing Vbracket 41 (FIGURES 4 to 6) has a horizontally disposed base portion with end sections-46 and 46' which areoftreduced width. Relatively small .slide plates -47 and 47 Vare secured on the bottom faces of the end sections 46 and -46' which ride on a pair of support rollers 48 and 43. The rollers 48 and 48' are mounted -for free rotation -on Vrelatively small shafts 49 and 49' which extend between a pair of opstanding guide plates 50 and 59. The guide plates d and Sil are disposed in parallel spaced relation on the top of the piston 42 so as Yto provide -a guideway or chamber which is open at the top and at the ends. The cross shafts 49 and 49' and the rollers 48 and V48 which they support are at an elevation which supports the bearing member 41 and its associated apparatus above the top Vedges of the vertical guide plates 5t) and 50'.V Pairs of guide blocks 51 and 51 are secured onY the ends of the top edges of the plates 50 and 59 so as to engage in sliding relation with the side edges of the end sections 46 and .46' of the base of the bearing member 41. Hold ldown bars S2 and 52' extend across the tops of the two pairs of side guide blocks 51 and 571 with' the ends of these bars and the guide blocks bolted down to lthe top edges of the plates 5t) and S. The hold down bars l52 and 52 engage in sliding relation with the top -surfaces of the end sections 46 and 46 of the bearing member 41 so that the swinging movement of the latter is coniin'ed to a predetermined path above the plates. 5 0

and Sil'. A center bearing roller 54 having a diameter slightly less than the distance between the inner opposed -faces of the plates 50 and 5b is mounted on a Vstub shaft or pin 55 depending from the bottom of the vbearing member 41. The movement of the bearing member 41 is conltrolled by means of a horizontally disposed pneumatic or hydraulic cylinder 56 which is mounted between the plates 50' and 58 with its piston 57 extending at opposite ends thereof so as to engage with the vertically disposed flanges 58 and 53 of angle bracket 59 and 59', The angle brackets 59 and 5% are secured by bolts or other fastening means to the bottom face of the bearing bracket 41 adjacent the slide plates 47 and 47' so that the depending anges 58 and 5S are confined within the housingformed between the guide plates 56 and 5G. The movement of the bearing member 41 is relatively small and is limited in each direction by cushion and stop members 60 and 60 which are mounted in the hold down bars 52 and 52'. Each stop member comprises a cylindrical housing and a spring pressed stop pin. 61 and 61' with thelatter disposed horizontally 'for `engagement with a l vertically extending wall portion `of the bearing member 41.

The cylindrical 56 is connected with an air or uid line through an electromagnetic valve (not shown) which is under the control of a pair of air operated switches 62 and `62 (FIGURE l). The switches 62 and 62' are supported in a housing forming bracket 63 which Yis slidably mounted for adjustment transversely of the machine on a bar support Y64 having its ends secured on the cross beam 14. The bracket 63 and its associated switches 62 and 62' are mounted adjacent the front end of the cross beam 1,4 with the switches in transversely spaced, sideby-side relation so that 'their operating ngers ,areV diS- posed opposite spaced apertures lin a horizontally disposed air control tube 65. The air tube 65 extends in a transverse direction across the open face of the bracket iand in outwardly spaced relation to the same and is secured by the bracket 66 to the housing forming bracket 63 with a suitable connection Ato a compressed air supply (not shown). The housing forming ybracket@ is adjustedfouV the support bar 6d so that the edge of thesanding belt 13, when the belt is tracking properly, moves Vin :apath which is between the two switches 62 and 62' witlifthe outer switch '.62 'being held closed by the unobstructed air stream from the tube and `the inner switch 62' being held Vopen due to the blocking of the air stream :from .the tube 65 by the interposed margin ofthe belt 13. As long as the Vbelt is tracking properly on the ro'lls 11 ,and 12, there is no swinging movement vof the top roll 11. When the belt 13 moves too far to the right, as viewed in FIG URE l, the innermost switch 62' is operated by the un covered air stream from the tube .65 and the operating cylinder 56 is actuated to swing the roll 11 in the proper direction to cause the beltfto moveto the Yleftonthe. roll 11. This movement is stopped when tbe belt moves vsutilciently to bring the edge lbetween .the two switches i62 and 62' thereby cutting ol the :air stream .to the .switch 62. If the belt moves too far to the left, as viewed in FIGURE l, vso as to cause margin of the belt to cover the air stream actuating vthe cuter switch 62, Ythe latter opens which operates kthe cylinder 56 to move the roll Y11 in the opposite direction, :thereby causing the belt :13 to move t-o the right until the edge reaches its proper path which uncovers the air streamtoperating switch 62 fand stops the swinging movement of the roll 11. ar rangement automatically positions the belt 'in proper tracking relation on the supporting rolls 11 and 12 lwith corrections being made in its path of travel in response to transverse movement ofthe belt.

The vertically disposed cylinders 43 and 43' are ,cond nected to fthe pneumatic or `hydraulic system 'to' provide for vertical movement of the 4pistons 42 and 42' 'the movement being equalizer] -by a shaft 66 gwhich lis ljour-g naled in the supporting beam 14 and carries at its @ppcsite ends pinions 67 and 67 which extend throughrslots in the cylinders 43 and 43 and engages with rack formations v68 and 63 provided on the pistons 42 and 42. The vertical movement of the pistons 42 and 42 `islimited by stop members 70 and 7G (FIGURE 5) which engage in the slots 71 and 71' -cut in the pistons 42 and 42. v'I'he pistons 42 and 42', of course, are urged upwardly to provide tension in the belt 13 through the tensioning roll 11, while the units is -in operation, the tension being re` lieved when it is necessary for the Vbelt to Ybe removed from the unit.

The shaft 4G has a reduced end portion 72 (FIGURE 4) on which axially spaced cylindrical bearing sleeves 73 are secured by lmeans of an end lock nut 74 which is threaded onto the end of the shaft section y7,2. The bear- -ing sleeves 73'cooperate `withassociated Vbearings75 to support the shaft end 72 in axially slidable and rotatable relation -in the bearing member 41. The shaft end72 is provided with an axially extending end recess 76 in whicha bearing 77 is seated and held therein by the. end lock screw 78. The outer end of the cylindrical `bearing forming portion of the bearing bracket d1 is closed by a combination cover and bracket plate 79 which is bolted thereto and on which the roll vibrating or reciprocating mechanism Sil is mounted.

The roll vibrating mechanism 8b (FIGURES 4 and 5) comprises a fluid motor having its cylinder 31 secured by a frame structure 82 to support plate 83 which is in turn bolted to spaced axially extending bracket arms Sfiand 8d. The cylinder 31 is mounted so that the piston 85 extends into the recess 76 in the end section 72 of the roll shaft dit and has its axis aligned with the axis of the shaft 4G. The piston 85 carries a bearing sleeve Se which is secured thereon and has a portion of reduced exterior diameter which extends through the bearing member 77 to receive a lock nut 87 on the threaded end so as to couple the piston to the shaft d0 for movement therewith in the axial direction while permitting relative rotational movement. A uid control valve S3 is mounted on a support plate 89 extending between the bracket arms S4 and 8d' while a liuid reversing poppet valve 9b is mounted in a bracket formation 91 provided therefor at the base of the plate member 79. A trip member 92 for the poppet valve, in the form of an elongate angle bar or plate, is secured to a collar or bracket plate 93 which is se ured on the piston sleeve member 86.

ln the operation of the apparatus, the beit 13 is placed on the rolls il and 12 from the lef side of the apparatus as viewed in FIGURE l, with the locking frame 1S being pivoted about the pin 253 to an open position and the upper roll 2li being lowered by downward or retractive movement of the bearing supporting pistons 42 and 42. With the belt i3 in position on the rolls 11 and 12 hydraulic fluid 4is supplied to the cylinders r3 and 43' through a suitable connection with the hydraulic system of the machine to tension the belt 13. The lowermost roll l2 is adjusted by rotation of the shaft 36 to bring the lowermost, work engaging portion of the belt to the proper elevation above the work supporting or carrying conveyor 17 for obtaining proper pressure between the belt and the work surface as the work pieces are conveyed beneath the roll 12. ri`he belt 13 is driven by the roll i2 which has its shaft 24tconnected to a polwer source and proper tracking of the belt 13 on the rolls l1 and l2 is obtained by operation of the cylinder 56 under the control of the air operated switches e2 ano 62. The upper belt carrying roll il is vibrated or oscillated independently of the belt tracking movements thereof by the vibrator mechanism 8G since the latter is mounted on the bearing member il with the piston 85 being connected to the end of the roll shaft in such a manner that the roll 1i is free to rotate relative to the piston d' and is moved in its axial direction by reciprocating movements of the piston SS, the latter being controlled automatically by the valve $9 which is actuated in response to movements of the piston 85. Since the vibrator mechanism Si) is carried on the bearing df. it is not affected by any swinging movements of the roll 11 which are required for proper belt tracking.

Wldie specific materials and particular details of construction have been referred to in describing the surface iinishing apparatus which is illustrated, it will be understood .that other materials and equivalent details of construction may be resorted to within the spirit of the invention.

I claim:

l. In a surface finishing machine, an upright supporting frame, a pair of transversely extending rolls mounted in vertically spaced relation on said frame and an endless traveling abrasive belt carried on said rolls, the uppermost one of said pair of rolls having a shaft, bearing forming bracket members at opposite ends of said frame which receive said shaft in rotatable sliding relation, a vertical pivot connecting the bearing bracket -at one end of said uppermost roll with the supporting frame, means connecting the bearing bracket member at the other end of said uppermost roll for sliding movement on the supporting frame in a direction transversely of said shaft, means operable in response to sidewise shifting of the abrasive belt for moving said last mentioned bearing bracket member relative to said frame so as to swing said uppermost roll about said vertical pivot and thereby maintain said abrasive belt in predetermined position on said rolls, and means mounted on said last mentioned bearing bracket member and connected to said shaft for automatically oscillating said shaft in an axial direction in said bearing bracket members independently of sidewise movement of the belt so as to vibrate the belt.

2. In a surface finishing machine, an upright supporting frame, means on said supporting frame for mounting thereon a pair of vertically spaced rolls, which means comprises bearing bracket members, a pair of vertically spaced rolls, an endless traveling abrasive belt supported on said pair of rolls, the uppermost one of said pair of rolls having a shaft, said shaft being mounted at its opposite ends in axially sliding relation in said bearing bracket members, pivot means connecting the bearing bracket member at one end of said uppermost roll with the supporting frame, means forming a sliding connection in a direction transversely of said shaft between the bearing bracket member at the other end of said uppermost roll and said supporting frame, means operable in response to sidewise shifting of the abrasive belt for moving said last mentioned bearing bracket member so as to swing said uppermost roll about said pivot means and thereby maintain said abrasive belt in predetermined position on said pair of rolls, and independently operating mechanism mounted on one of said bearing bracket members and connected to the Vadjacent end of said shaft for oscillating said shaft in an axially extending path so as to impart uniform back and forth movement to said uppermost roll and vibrate the abrasive belt Without regard to sidewise shifting thereof.

3. In a surface finishing machine, an upright supporting frame, bearing forming end bracket members on said supporting frame, a pair of vertically spaced rolls journaled in said end bracket members, an endless traveling abrasive belt on said pair of rolls, the uppermost one of said pair of rolls having a shaft, which shaft is mounted at its opposite ends in axially sliding relation in said bearing forming end bracket members, one of said end bracket members at one end of said uppermost roll having a pivoted connection with the supporting frame, means connecting the other one of said end bracket members to the supporting frame for sliding movement thereon so as to swing said uppermost roll about said pivoted connection, means operable in response to sidewise shifting of the abrasive belt for moving said last mentioned end bracket member relative to said supporting frame so as to cause said abrasive belt to travel in a predetermined path on said pair of rolls, and a belt vibrating mechanism at one end of said uppermost roll shaft comprising an hydraulic cylinder supported with its piston in axial alignment with said uppermost roll shaft and connected thereto so as to oscillate said uppermost roll shaft in the axial direction thereof without interfering with the rotation of said uppermost roll shaft and independently of swinging movement of said uppermost roll.

4. In a surface finishing machine, an upright frame, an endless traveling abrasive belt and vertically spaced end supports for said belt mounted on said upright frame, the lowermost one of said belt end supports being arranged to press the belt against the work and the uppermost one of said belt end supports comprising a roll, a shaft for said roll, bearing members in which opposite ends of said shaft are mounted in axially sliding relation, and means carried on one of said bearing members for imparting a reciprocating movement to said shaft in the direction of its axis of rotation which means comprises a support bracket, a fluid motor mounted on the apa-mesa bracket and having' a -piston extending-ain :the directiomof the axis of :said ishaft, fmeans iconnecting the :end of Said shaft AWith the piston lof Vthe fluid motor so as to rmove therevvith'and to rotate. relativeithereto, and vmeans-responsive ,to'movements of said piston .to Vcontrol the flow of uid to .said motoriwhereby to reciprocate :said :shaft 55. .A :traveling belt Ytype surface Afinishing machine comprising a vertically `dsposedtsupporting frame, a traveling abrasive belt, parallel, yerticallyispaced heltsupporting rolls, said rolls having supporting shafts, upper and lower :bearing members ,mounted ,on said -frarne which receive zoppositerends 1of saidsupporting shafts, and means for imparting tothe upper v.one .of said rolls fa reciprocating rnotion in @the direction :of the -axis of its :supporting shaft, which means inludes a bracket :plate secu-red on the end .'face of one of said upper -bearin'g members, a pair of spaced, axially extending bracket arms on said Y bracket plate, a cross :bar connecting said -bracket arms,

a-uid operated :motor mounted on `saicl lcross bar and having :a piston which extends-in `axial alignment with the shaft of said upper roll, said upper Yroll supporting shaft having a -recess in one end ithereof, a ,bearing confined 8 in said recess, said piston having la sleeve member on the outer end thereof which sleeve extends into said recess and through said bearing and a nut on the end of said sleeve member for connecting said sleeve to said References Cited in vthe'le of this patent UNITED vSTA'IES PATENTS 781,423 Hemming Ian. -31, 1905 890,463 Soules June 9, 1908 20 1,938,758 Ernst Dec. v12, 1933 2,597,256 Murray May .20, '1952 2,744,363 Gluck a May 8, 1956 

1. IN A SURFACE FINISHING MACHINE, AN UPRIGHT SUPPORTING FRAME, A PAIR OF TRANSVERSELY EXTENDING ROLLS MOUNTED IN VERTICALLY SPACED RELATION ON SAID FRAME AND AN ENDLESS TRAVELING ABRASIVE BELT CARRIED ON SAID ROLLS, THE UPPERMOST ONE OF SAID PAIR OF ROLLS HAVING A SHAFT, BEARING FORMING BRACKET MEMBERS AT OPPOSITE ENDS OF SAID FRAME WHICH RECEIVE SAID SHAFT IN ROTATABLE SLIDING RELATION, A VERTICAL PIVOT CONNECTING THE BEARING BRACKET AT ONE END OF SAID UPPERMOST ROLL WITH THE SUPPORTING FRAME, MEANS CONNECTING THE BEARING BRACKET MEMBER AT THE OTHER END OF SAID UPPERMOST ROLL FOR SLIDING MOVEMENT ON THE SUPPORTING FRAME IN A DIRECTION TRANSVERSELY OF SAID SHAFT, MEANS OPERABLE IN RESPONSE TO SIDEWISE SHIFTING OF THE 